Combined shock-absorber and air-pump for automobiles.



L. W. LOMBARD. COMBINED SHOCK ABSORBER AND AIR PUMP FOR AUTOMOBILES;

APPLICATION FILED JULY 23, 1914.

Patented Aug. 31, 1915.

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LEVI W. LOMBARD, 0F WALTHAM, MASSACHUSETTS, ASSIG-N'OR T0 FEDERALENGINEERING COMPANY, OF NEWTON, MASSACHUSETTS, A COPEORATION OFMASSACHUSETTS.

anson.

Specification of Letters Patent.

Patented Aug. 31, 1915.

Application filed July 23, 1914. Serial No. 862,702.

To all whom it may concern:

Be it known that I, LEVI W. LOMBARD, citizen of the United States,residing at VValtham, county of Middlesex, State of Massachusetts, haveinvented a certain new and useful Improvement in CombinedShock-Absorbers and Air-Pumps for Automobiles, of which the following isa specification, reference being had therein to the accompanyingdrawings.

My invention has for its object to provide a shock absorber forautomobiles which shall have the effect of taking up the shocks due tounevenness in the road surface and preventing their transmission to thebody of the automobile and at the same time shall operate as an air pumpto supply air under pressure to a tank for use in operating a compressedair self starter for filling pneumatic tires and for such other purposesas may be required. While other attempts have been made to providecombined shock absorbers and air pumps difficulty has been experiencedin producing a device which will furnish a supply of. air at highpressure at times when the car is traveling over a relatively smoothroad which produced oscillations of narrow amplitude between the runninggear and the frame.

The device embodying my invention is so constructed that even very smalloscillations will pump air at a high pressure and the efiiciency of thedevice as a shock absorber A is increased rather than diminished.

While I have described and shown only a single form of my device in theaccompanying drawings, I do not limit myself to this construction sinceI am fully aware that it is capable of embodiment in a variety of forms.

For the purpose of illustrating the breadth of the invention, it may besaid that an essential feature is the employment of a hollow piston orcylinder which cooperates as a piston with another exterior cylinder,and also cooperates as a cylinder with an in: terior piston, therebyforming two combina tions of piston and cylinder, so that, suitablevalves being provided, one combination acts as an air pump and the otheras a shock absorber.

Another equally important feature of my invention is the arrangement 'sothat the first part of the oscillation between the running gear andframe operates the air-pump combination while the further or succeedinggravel operates the shock absorber combina- The device embodying myinvention is extremely simple and all the working parts are inclosedwithin the main cylinder so that the possibility of injury or loss ofadjustment is reduced to a minimum. The device may also be installed inplace of one of the two or four shock absorbers ordinarily employed.

The invention will be fully understood from the following descriptiontaken in connection with the accompanying drawings, and the novelfeatures thereof will be pointed out and clearly defined in the claimsat the close of the specification.

Referring to the drawings,the figure is a vertical section of the deviceembodying my invention in its preferred form.

At 11 is shown, the body or main cylinder closed at the lower end by acap 12 provided with a ball 13 for connection with a bracket, not shown,on the lower spring or axle or running gear of the car. The upper end isclosed by a cap 14 having thereon a hollow boss 15 and having a properaperture to allow the piston rod '16 to slide therein. The piston rod 16is provided at its upper end with the ball 17 which is secured to abracket, not shown, on the body or frame of the car. Within the cylinder11 is located a main piston or auxiliary cylinder 18 provided with astiff spring packing ring 19 which exerts considerable pressure on thewalls of the cylinder and prevents the passage of air past the piston.The spring ring 19 also engages the wall of the cylinder so strongly asto require a considerable force to be exerted to move it vertically inthe cylinder. The main piston 18 divides the interior of the cylinder 11into two chambers 20 and 21 respectively which are vented to theatmosphere by ports 22 and 23, located at a short distance from the endsof the cylinder, so that when the piston passes one of these ports anair cushion will be formed in the end of the cylinder. The main piston18 is hollow and contains within it an auxlower end of the piston rod 16by screw threads or the like and the piston rod passes out through astuffing box 30 provided with a nut 31 and suitable packing 32. Thelower end of the chamber contained within the main piston is closed by acap 33 and the 'ends of the chamber are cushioned by thin layers ofelastic material designated 34 and 35. At 36 and 37 are. shown two portsleading from the upperchamber 20 into the upper auxiliary chamber 25 andfrom the lower chamber 21 to the lower auxiliary chamber 26. These twoports are controlled by two valves 38 and 39, both of which are carriedon a stem 40 which slides in a suitable hole in the auxiliary piston 24.Small hollows 41 and 42 are formed in the upper and lower faces of theaum liary piston so that the auxiliary piston may move the entire lengthof the auxiliary chamber without doing injury to the valves.

' At 43 is shown a valve chamber containing a ball '44 or other suitablevalve member. The valve chamber 43 is connected with the upper auxiliarychamber 25 by one or more ports 45 and with the lower auxiliary chamber26 by two other ports 46.

The valve chamber 43 is conveniently constructed by drilling a holethrough the piston and closing the hole by two screw threaded plugs 47and 48, the ports 45, 46 being I drilled through the respective plugs.The

valve chamber 43 communicates with an air passage 49 formed partly inthe auxiliary piston 24 and partly in the piston rod 16; This passagealso extends into a hose connection 50 by which'the compressed air produced by the action of the device is carried away into the tank or otherstorage space.

At 52 is shown a valve which prevents the flow of air back into thevalve chamber. The operation of my device is as follows,- The movementof the car over the surface of the roadway produces oscillations betweenthe frame and the axles which move the piston rod 16 relatively to themain cylinder 11, and it has been found by 'careful study that even onthe smoothest roads and at slow speed oscillations of an inch or moreresult almost continuously. Assuming for convenience, that'the firstoscillatory movement tends to bring the axle nearer to the frame of thecar thereby moving the cylinder upward or the piston downward, as shownin the drawing, it will be seen that the auxiliary piston will movedownward compressing the air inthe lower auxiliary chamber 26 and thatthe ball valve 44 will fly upward and close the ports 45 so that the aircontained in the lower auxiliary chamber 26 will then escape through theports 46 and the air passage 49 past the valve 52. The downward movementof the auxiliary piston will contine until it strikes the elasticcushion 35 or until the pressure of the air in the lower auxiliarychamber becomes so great that the friction between the main piston andthe wall of the main cylinder are overcome. to this point the device hasoperated solely as a pump. The operation as the shock absorber nowbegins. The main piston then moves downwardly in the lower main chamber21 compressing the air therein which escapes through the vent 23. Thismovement continues until the position of equilibrium is reached. Thedownward movement of the auxiliary piston while the main piston remainsstationary causes air to be drawn in through the port 36 from-the uppermain per auxiliary chamber is free to flow through into the passage 49leading to the air tank.

From the foregoing it will be seen that even the smallest movements of acar such as are produced on smooth roads will cause the device to pumpair under high pressure and at the same time the cushioning efiect ofthe device is increased rather than diminished because the auxiliarypiston moves for a short distance before the main piston begins to move,thereby easing the action of the device.

'While I have describedthe action of my device as if the main pistonremains stationary until the completion of the pumping stroke, it ispossible that relative movements between the two pistons may occur whileboth pistons are moving. This, however, does not affect the portion ofthe device which depends on a movement of the auxiliary pistonrelatively to that of the main piston, it being immaterial whether thistakes place while the main pistonis stationary or while it is moving.

I claim- 1. In a combined shock absorber and air pump, amain cylinder, ahollow piston forming an auxiliary cylinder, a piston in said auxiliarycylinder, said hollow piston or auxiliary cylinder being provided withports leading into the main cylinder, valves controlling said ports,other ports in the piston in said auxiliary cylinder and valvescontrolling them, said elements forming two combinations of piston andcylinder one of said combinations acting as a shock absorber and theother as an air pump.

2. The combined shock absorber and air pump comprising a cylinder, apiston within the cylinder, said piston having a cylindrical chambertherein, an auxiliary piston in said chamber, said cylinder and saidauxiliary piston being secured one to the frame and the other to therunning gear, and suitable valves whereby the movement of the frame andrunning gear relatively to each other first operate the auxiliary pistonas a pump and then the main piston as a shock absorber.

In the combined shock absorber and air pump, a main cylinder closed atits ends, an auxiliary hollow cylinder contained within said maincylinder and fitting the bore thereof inclosed at its ends, a pistonwithin the auxiliary cylinder and fitting the bore thereof, said partsbeing provided with suitable ports, valves controlling said ports, saidelements forming two combinations of piston and cylinder, one acting asa shock absorber and the other as an air pump.

4. The combined shock absorber and air pump comprising a cylinder, apiston therein, said piston having a cylindrical chamber therein, anauxiliary piston, said cylinder and said piston rod being secured one tothe frame and the other to the running gear, there being a passageleading through the piston rod into the chamber within the main piston,and passages leading through the ends of the main piston into the maincylinder, and valves controlling the said passages whereby the movementof the frame and the running gear relatively to each other first operate the auxiliary piston as a pump then the main piston as a shockabsorber.

In testimony whereof I affix my signature, in presence of two witnesses.

LEVI W. LOMBARD.

Witnesses:

EDWIN M. BRooKs, GEORGE P. DIKE.

